Aliphatic compounds as fragrants with musk characteristics

ABSTRACT

This invention relates to aliphatic carbonyl compounds of formula I wherein, their manufacture and their use in fragrance compositions. R1 to R4, X and Y have the meaning as described in the specification

This invention relates to novel compounds having musk characteristics,their manufacture and their use in fragrance compositions.

Conventional compounds having musk characteristics have been selectedfrom nitro arenes, polycyclic aromatics and macrocyclic compounds.However, in recent years there has been great activity to find novelcompounds having musk characteristics to replace these conventionalmusks, the use of which is becoming more restricted because of, e.g.environmental concerns.

Already more than ten years ago the first alicyclic compounds havingmusk characteristics have been described, exemplified by the productHelvetolide® (4-(3,3-dimethyl-1-cyclohexyl)-2,2-dimethyl-3-oxapentylpropionate, trademark of Firmenich SA, Switzerland).

Surprisingly, we now found certain aliphatic carbonyl compounds thathave musk characteristics and a high impact in perfume formulations.This new class of compounds has not been described before in theliterature.

Thus, the present invention refers in a first aspect to a compound offormula I

wherein

-   R¹ and R³ are independently hydrogen, methyl, or ethyl;-   R² is hydrogen, methyl, ethyl, methylene, or ethylidene;-   R⁴ is C₁ to C₄ alkyl, for example methyl, ethyl, i-propyl, n-propyl,    cyclopropyl, sec-butyl, n-butyl, tert-butyl, or cyclobutyl; or-   R⁴ is vinyl or a linear, branched or cyclic C₃ to C₄ alkenyl, for    example propen-1-yl, propen-2-yl, prop-2-en-1-yl,    cyclobut-1-en-1-yl, butenyl, e.g. but-1-en-1-yl, or butadiene;-   X is carbonyl or a divalent radical —(CMe₂)-;-   Y is oxygen or a divalent radical —(CH₂)—;-   the bond between C-2 and R² is a single bond, and the bond between    C-2 and C-3 together with the dotted line represents a double bond;    or-   the bond between C-2 and C-3 is a single bond, and the bond between    C-2 and R² together with the dotted line represents a double bond;    or-   the bond between C-2 and R² is a single bond and the bond between    C-2 and C-3 is a single bond.

The compounds according to the present invention comprise one or morechiral centres and as such may exist as a mixture of stereoisomers, orthey may be resolved as isomerically pure forms. Resolving stereoisomersadds to the complexity of manufacture and purification of thesecompounds and so it is preferred to use the compounds as mixtures oftheir stereoisomers simply for economic reasons. However, if it isdesired to prepare individual stereoisomers, this may be achievedaccording to methodology known in the art, e.g. preparative HPLC and GCor by stereoselective syntheses.

Preferred compounds are unsaturated aliphatic carbonyl compounds offormula I, i.e. compounds of formula I wherein the bond between C-2 andR² is a single bond, and the bond between C-2 and C-3 together with thedotted line represents a double bond; or the bond between C-2 and C-3 isa single bond, and the bond between C-2 and R² together with the dottedline represents a double bond, e.g. acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester, propionicacid 2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)-propyl ester,cyclopropanecarboxylic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester, butyricacid 2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester,isobutyric acid 2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propylester, 2-methylacrylic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester,but-2-enoic acid 2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propylester, but-3-enoic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester, propionicacid (1″,2″,4″-trimethylpent-2″-enyloxy)carbonylmethyl ester,6-methyl-6-(1′,2′,4′-trimethylpent-2′-enyloxy)heptan-3-one, propionicacid 2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)-propyl ester,cyclopropanecarboxylic acid2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)propyl ester, butyricacid 2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)propyl ester,4-oxopentanoic acid 1′,4′,4′-trimethylpent-2′-enyl ester, propionic acid2′-(1″,4″-dimethylpent-2″-enyloxy)-2′-methylpropyl ester andcyclopropanecarboxylic acid2′-(1″,4″-dimethylpent-2″-enyloxy)-2′-methylpropyl ester.

Particular preferred compounds of formula I are represented by thegeneral formula

wherein

-   R¹ and R² are independently hydrogen or methyl;-   R⁴ is C₁ to C₄ alkyl, for example methyl, ethyl, i-propyl, n-propyl,    cyclopropyl, sec-butyl, n-butyl, tert-butyl, or cyclobutyl; or-   R⁴ is vinyl or a linear, branched or cyclic C₃ to C₄ alkenyl, for    example propen-1-yl, propen-2-yl, prop-2-en-1-yl,    cycloprop-1-en-1-yl, cycloprop-2-en-1-yl, cyclobut-2-en-1-yl,    butenyl, e.g. but-1-en-1-yl, or butadiene.

Compounds of formula I wherein the bond between C-2 and R² is a singlebond, and the bond between C-2 and C-3 together with the dotted linerepresents a double bond are preferred in their (2″E)-configuration. Asillustrated in the examples the compounds in their (2″E)-configurationpossess a more intense odour than the compounds in the corresponding(2″Z)-configuration.

Thus, the present invention refers in a further aspect to compound offormula I wherein the bond between C-2 and R² is a single bond, and C-2and C-3 together with the dotted line represents a double bond, enrichedin one of the double bond isomers, i.e. (E)- or (Z)-configurated doublebond.

The term “enriched” is used herein for a compound having an isomericpurity of over 1:1 in favour of the selected double bond isomer.Compounds are preferred having a purity of about 55:45 or greater, e.g.about 70:30.

The compounds according to the present invention may be used alone or incombination with known odourant molecules selected from the extensiverange of natural and synthetic molecules currently available, such asessential oils, alcohols, aldehydes and ketones, ethers and acetals,esters and lactones, macrocycles and heterocycles, and/or in admixturewith one or more ingredients or excipients conventionally used inconjunction with odourants in fragrance compositions, for examplecarrier materials, and other auxiliary agents commonly used in the art.

The following list comprises examples of known odourant molecules, whichmay be combined with the compounds of the present invention:

-   -   ethereal oils and extracts, e.g. castoreum, costus root oil, oak        moss absolute, geranium oil, jasmine absolute, patchouli oil,        rose oil, sandalwood oil or ylang-ylang oil;    -   alkohols, e.g. citronellol, Ebanol™, eugenol, geraniol, Super        Muguet™, linalool, phenylethyl alcohol, Sandalore™, terpineol or        Timberol™.    -   aldehydes and ketones, e.g. α-amylcinnamaldehyde, Georgywood™,        hydroxycitronellal, Iso E Super®, Isoraldeine™, Hedione®,        maltol, methyl cedryl ketone, methylionone or vanillin;    -   ether and acetals, e.g. Ambrox™, geranyl methyl ether, rose        oxide or Spirambrene™.    -   esters and lactones, e.g. benzyl acetate, cedryl actetate,        γ-decalactone, Helvetolide®, γ-undecalactone or vetivenyl        acetate.    -   macrocycles, e.g. ambrettolide, ethylene brassylate or        Exaltolide®.    -   heterocycles, e.g. isobutylchinoline.

However, due to their unique character, the compounds of formula I areespecially well suited for use in fresh musky accords, woody-spicy orfloral-hesperidic compositions as is more specifically illustrated inthe Example.

The compounds of the present invention may be used in a broad range offragrance applications, e.g. in any field of fine and functionalperfumery, such as perfumes, household products, laundry products, bodycare products and cosmetics. The compounds can be employed in wideranging amounts depending upon the specific application and on thenature and quantity of other odourant ingredients that may be, forexample, from about 0.001 to about 20 weight percent. In one embodimentcompounds of the present invention may be employed in a fabric softenerin an amount of about 0.001 to 0.05 weight percent. In anotherembodiment compounds of the present invention may be used in analcoholic solution in amounts of about 0.1 to 20 weight percent, morepreferably between about 0.1 and 5 weight percent. However, these valuesshould not be limiting on the present invention, since the experiencedperfumer may also achieve effects or may create novel accords with loweror higher concentrations.

The compounds of the present invention may be employed into thefragrance application simply by direct mixing the fragrance compositionwith the fragrance application, or they may, in an earlier step beentrapped with an entrapment material, for example, polymers, capsules,microcapsules and nanocapsules, liposomes, precursors, film formers,absorbents such as for example by using carbon or zeolites, cyclicoligosaccharides and mixtures thereof, or they may be chemically boundto substrates which are adapted to release the fragrance molecule uponapplication of an exogenous stimulus such as light, enzyme, or the like,and then mixed with the application.

Thus, the invention additionally provides a method of manufacturing afragrance application, comprising the incorporation of a compound offormula I as a fragrance ingredient, either by directly admixing thecompound of formula I to the application or by admixing a fragrancecomposition comprising a compound of formula I, which may then be mixedto a fragrance application, using conventional techniques and methods.

As used herein, “fragrance application” means any product, such as fineperfumery, e.g. perfume and Eau de Toilette; household products, e.g.detergents for dishwasher, surface cleaner; laundry products, e.g.softener, bleach, detergent; body care products, e.g. shampoo, showergel; and cosmetics, e.g. deodorant, vanishing creme, comprising anodourant. This list of products is given by way of illustration and isnot to be regarded as being in any way limiting.

Compounds of formula I wherein X is a divalent radical —(CMe₂)-, and Yis oxygen, i.e. oxa esters, may be synthesized by etherification of anappropriately substituted allylic alcohol with isobutylene oxide andsubsequent esterification with an appropriately substituted carboxylicacid. The resulting compounds may be hydrogenated in a known manner togive further compounds of formula I.

Compounds of formula I wherein X is carbonyl and Y oxygen, i.e.diesters, may be synthesized by esterification of an appropriatelysubstituted allylic alcohol with chloroacetic acid, followed by furtheresterification with an appropriately substituted carboxylic acid. Theresulting compounds may be hydrogenated in a known manner to givefurther compounds of formula I.

Compounds of formula I wherein X is carbonyl and Y is a divalent radical—(CH₂)—, i.e. oxo esters, may be prepared by esterification of anappropriately substituted allylic alcohol with an appropriatelysubstituted oxo carboxylic acid, e.g. laevulinic acid.

Compounds of formula I wherein X is a divalent radical —(CMe₂)- and Y isa divalent radical —(CH₂)—, i.e. oxa ketones, may be prepared byetherification of an appropriately substituted allylic alcohol withisobutylene oxide, subsequent oxidation to the aldehyde, followed byWittig-Homer-Emmons reaction under conditions known to the skilledperson and selective hydrogenation of the formed double bond. Theresulting compounds may be further hydrogenated in a known manner togive further compounds of formula I.

The aforementioned substituted allylic alcohol starting material isaccessible by reduction of an aldol-condensation product, as known inthe art.

Further particulars as to reaction conditions are provided in theexamples.

There now follows a series of examples that illustrate the invention.

EXAMPLE 1 (2″E/Z) Acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester

Within a period of 90 min., a solution of triethyl 2-phosphonopropionate(238 g, 1.00 mol) in dimethoxyethane (DME, 150 ml) was added dropwisewith stirring under an atmosphere of N₂ to a solution of NaH (43.6 g,1.00 mol) in DME (600 ml). The mixture was then heated to reflux, andafter 15 min. at reflux temp., isobutyric aldehyde (72.1 g, 1.00 mol)was added dropwise. After a further 30 min. stirring at reflux, themixture was poured into ice/water (1:1, 1 L). AcOH (60 ml) was added,and the product was extracted with Et₂O (2×200 ml). The combined organicextracts were washed with water (400 ml) and brine (100 ml), dried(Na₂SO₄), and concentrated in a rotary evaporator. The resulting residuewas distilled to provide at 86-75° C./27 mbar 117 g (75%) of2,4-dimethylpent-2-enoic acid ethyl ester.

A mixture of 2,4-dimethylpent-2-enoic acid ethyl ester (116 g, 742 mmol)and KOH 85% (147 g, 2.23 mol) in water/EtOH (1:1, 2.0 L) was refluxedfor 1 d. The EtOH was stripped off on a rotary evaporator, and theremaining mixture was washed with Et₂O. The combined ethereal washingswere extracted with 2 N aq. NaOH (100 ml), and all aqueous solutionswere combined. Under cooling with an ice/water bath, conc. aq. H₃PO₄(200 ml) was added to adjust the combined aqueous solutions to pH 3, andthe product was extracted with Et₂O (200 ml). The ethereal solution waswashed with water (200 ml) and brine (25 ml). After drying (Na₂SO₄), thesolvent was evaporated in a rotary evaporator to furnish 94.2 g (99%) of2,4-dimethyl-pent-2-enoic acid.

Under an atmosphere of N₂, a 1.6 M solution of MeLi in Et₂O (500 ml, 800mmol) was added during 105 min. dropwise with stirring between 0-10° C.to a solution of 2,4-dimethylpent-2-enoic acid (41.0 g, 320 mmol) inEt₂O (1.6 L). The reaction mixture was heated to reflux for 1 h, andthen between 5-15° C. 5 N HCl (200 ml) was added dropwise. The organiclayer was separated, the aqueous one extracted with Et₂O (200 ml). Thecombined organic solutions were washed with water (200 ml) and brine(100 ml), dried (Na₂SO₄) and concentrated in a rotary evaporator toafford crude 3,5-dimethylhex-3-en-2-one, which was taken up in Et₂O (160ml). Under N₂ at room temp., this solution was added dropwise withstirring to a suspension of LAH (3.34 g, 880 mmol) in Et₂O (320 ml)during 1 h. The reaction mixture was refluxed for 2 h, and then quenchedbetween 0-5° C. by addition of water (10 ml) and brine (20 ml). Theorganic layer was separated and the aqueous one extracted with Et₂O (100ml). The combined ethereal extracts were washed with water (100 ml) andbrine (50 ml), dried (Na₂SO₄), and concentrated under reduced pressure.Silica-gel FC (pentane/Et₂O, 4:1, R_(f)=0.40) of the resulting residueprovided 34.7 g (85% over 2 steps) of 3,5-dimethylhex-3-en-2-ol.

At 0° C. under N₂, a 1 M solution of MeAlCl₂ (50 ml, 50 mmol) in hexanewas added dropwise with stirring during a period of 1 h to a solution of3,5-dimethylhex-3-en-2-ol (12.8 g, 100 mmol) and isobutylene oxide (8.65g, 120 mmol) in cyclohexane (100 ml). The cooling bath was removed, andstirring was continued for 16 h, prior to pouring the mixture intoice/water (1:1, 100 ml). The resulting slurry was dissolved by additionof conc. aq. H₃PO₄, and the product extracted with Et₂O (2×100 ml). Thecombined organic extracts were washed with water (100 ml) and brine (25ml), dried (Na₂SO₄) and concentrated in a rotary evaporator. Theresulting residue was purified by silica-gel FC (pentane/Et₂O, 19:1,R_(f)=0.12) to afford 3.10 g (15%) of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol.

At 0° C. under N₂, N,N′-Dicyclohexylcarbodiimide (DCC, 1.03 g, 5.00mmol) was added to a stirred solution of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (830 mg, 4.14mmol), acetic acid (250 mg, 4.14 mmol) and 4-(dimethylamino)pyridine(DMAP, 50 mg, 410 mmol) in CH₂Cl₂ (10 ml). After stirring for 1 h atroom temp., the precipitate was vacuum filtrated and washed with CH₂Cl₂.The combined filtrates were concentrated under reduced pressure, and theresulting residue was purified by silica-gel FC (pentane/Et₂O, 19:1,R_(f)=0.36) to furnish 710 mg (71%) of the odouriferous title compound.

IR (ATR): ν=1232/1044 cm⁻¹ (s, νC—O), 1744 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.91/0.92/0.93/0.95 (4d, J=6.5 Hz, 6H, 4″-Me₂), 1.14/1.15(2d, J=6.5 Hz, 3H, 1″-Me), 1.17/1.18 (2s, 6H, 2′-Me₂), 1.60/1.68 (2d,J=1.5 Hz, 3H, 2″-Me), 2.07/2.08 (2s, 3H, 2-H₃), 2.48/2.60 (2m_(c), 1H,4″-H), 3.89/3.90/3.99/4.00 (4d, J=11.0, 2H, 1′-H₂), 4.01/4.57 (2q, J=6.5Hz, 1H, 1″-H), 4.85/5.14 (2d, J=9.5 Hz, 1H, 3″-H).—¹³C NMR (CDCl₃):δ=11.1/17.6 (2q, 2″-Me), 20.7/20.8 (2q, C-2),22.3/22.4/22.6/22.8/23.1/23.3 (6q, 1″-Me, 4″-Me₂), 23.4/23.5/23.5/23.6(4q, 2′-Me₂), 26.4/26.5 (2d, C-4″), 66.0/73.3 (2d, C-1″), 69.7/69.8 (2t,C-1′), 74.1/74.2 (2s, C-2′), 131.6/131.9 (2d, C-3″), 136.3/136.7 (2s,C-2″), 170.7/170.7 (2s, C-1).—MS (70 eV); m/z=242 (1) [M⁺], 227 (1)[M⁺-CH₃], 199 (1) [M⁺-C₃H₇], 115 (42) [C₆H₁₁O₂ ⁺], 111 (46) [C₈H₁₅ ⁺],110 (30) [C₈H₁₄ ⁺], 95 (26) [C₈H₁₄ ⁺—CH₃], 81 (7) [C₈H₁₄ ⁺—C₂H₅], 69(45) [C₈H₁₄ ⁺—C₃H₅], 55 (30) [C₄H₇ ⁺], 43 (100) [C₃H₇ ⁺].—C₁₄H₂₆O₃(242.4): calcd. C, 69.38; H, 10.81. found C, 69.51; H, 11.02.

Odour description: floral, musky, fruity-green.

GC Olfactometry: (E/Z)=45:55, both isomers smell musky, the E-isomer ismore intense.

Example 2 (2″E/Z) Propionic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)-propyl ester

Following the procedure for the synthesis of (2″E/Z) acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 1), Steglich esterification of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (830 mg, 4.14mmol) with propanoic acid (310 mg, 4.14 mmol) and purification bysilica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.50) furnished 690 mg (65%) ofthe odouriferous title compound.

IR (ATR): ν=1072/1169 cm⁻¹ (s, νC—O), 1741 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.91/0.92/0.93/0.95 (4d, J=6.5 Hz, 6H, 4″-Me₂), 1.14/1.15(2d, J=6.5 Hz, 3H, 1″-Me), 1.16/1.16 (2t, J=8.0 Hz, 3H, 3-H₃), 1.17/1.18(2s, 6H, 2′-Me₂), 1.60/1.68 (2d, J=1.5 Hz, 3H, 2″-Me), 2.36/2.36 (2q,J=8.0 Hz, 2H, 2-H₂), 2.48/2.59 (2m_(c), 1H, 4″-H), 3.90/3.91/3.99/4.00(4d, J=11.0, 2H, 1′-H₂), 4.02/4.57 (2q, J=6.5 Hz, 1H, 1″-H), 4.85/5.14(2d, J=9.5 Hz, 1H, 3″-H).—¹³C NMR (CDCl₃): δ=8.96/8.96 (2q, C-3),11.1/17.6 (2q, 2″-Me), 22.3/22.4/22.6/22.8/23.1/23.3 (6q, 1″-Me,4″-Me₂), 23.4/23.5/23.6/23.6 (4q, 2′-Me₂), 26.4/26.5 (2d, C-4″),27.4/27.5 (2t, C-2), 66.0/73.3 (2d, C-1″), 69.6/69.7 (2t, C-1′),74.2/74.3 (2s, C-2′), 131.5/131.8 (2d, C-3″), 136.3/136.7 (2s, C-2″),174.1/174.1 (2s, C-1).—MS (70 eV); m/z=256 (1) [M⁺], 241 (1) [M⁺-CH₃],147 (1) [C₇H₁₅O₃ ⁺], 129 (27) [C₇H₁₃O₂ ⁺], 111 (52) [C₈H₁₅ ⁺], 110 (28)[C₈H₁₄ ⁺], 95 (26) [C₈H₁₄ ⁺—CH₃], 81 (9) [C₈H₁₄ ⁺—C₂H₅], 69 (40) [C₈H₁₄⁺—C₃H₅], 57 (100) [C₄H₉ ⁺].—C₁₅H₂₈O₃ (256.4): calcd. C, 70.27; H, 11.01.found C, 70.50; H, 11.18.

Odour description: powerful, musky, fruity, slightly green.

GC Olfactometry: (E/Z)=45:55, both isomers smell musky, the E-isomer ismore intense.

Example 3 (2″E/Z) Cyclopropanecarboxylic acid2′-methyl-2′-(1″,2″,4″-trimethyl-pent-2″-enyl-oxy)propyl ester

Following the procedure for the synthesis of (2″E/Z) acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″enyloxy)propyl ester (see Example1), Steglich esterification of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (830 mg, 4.14mmol) with cyclopropane carboxylic acid (360 mg, 4.14 mmol) andpurification by silica-gel FC (pentane/Et₂O, 99:1, R_(f)=0.07) furnished680 mg (61%) of the odouriferous title compound.

IR (ATR): ν=1163/1072 cm⁻¹ (s, νC—O), 1731 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.85/0.85 (2 m_(c), 2H, 3-,4-H_(b)), 0.91/0.92/0.95/0.95 (4d,J=6.5 Hz, 6H, 4″-Me₂), 1.00/1.01 (2m_(c), 2H, 3-,4-H_(a)), 1.14/1.15(2d, J=6.5 Hz, 3H, 1″-Me), 1.17/1.18/1.18/1.19 (4s, 6H, 2′-Me₂),1.63/1.64 (2m_(c), 2H, 2-H), 1.60/1.69 (2d, J=1.5 Hz, 3H, 2″-Me),2.49/2.61 (2m_(c), 1H, 4″-H), 3.89/3.90/3.99/4.01 (4d, J=11.0, 2H,1′-H₂), 4.01/4.58 (2q, J=6.5 Hz, 1H, 1″-H), 4.85/5.14 (2d, J=9.5 Hz, 1H,3″-H).—¹³C NMR (CDCl₃): δ=8.13/8.13/8.15/8.15 (4q, C-3,-4), 11.1/17.6(2q, 2″-Me), 12.7/12.8 (2d, C-2), 22.3/22.4/22.7/22.8/23.1/23.3 (6q,1″-Me, 4″-Me₂), 23.5/23.6/23.6/23.6 (4q, 2′-Me₂), 26.4/26.5 (2d, C-4″),66.0/73.3 (2d, C-1″), 69.6/69.7 (2t, C-1′), 74.2/74.3 (2s, C-2′),131.6/131.9 (2d, C-3″), 136.3/136.7 (2s, C-2″), 174.4/174.5 (2s,C-1).—MS (70 eV); m/z=268 (1) [M⁺], 253 (1) [M⁺-CH₃], 225 (1) [M⁺-C₃H₇],159 (2) [C₈H₁₅O₃ ⁺], 141 (17) [C₈H₁₃O₂ ⁺], 111 (38) [C₈H₁₅ ⁺], 110 (20)[C₈H₁₄ ⁺], 95 (16) [C₈H₁₄ ⁺—CH₃], 81 (6) [C₈H₁₄ ⁺—C₂H₅], 69 (100) [C₈H₁₄⁺—C₃H₅], 55 (21) [C₄H₇ ⁺], 41 (27) [C₃H₅ ⁺]. —C₁₆H₂₈O₃ (268.4): calcd.C, 71.60; H, 10.52. found C, 71.66; H, 10.70.

Odour description: powerful, musky, sweet, slightly fruity.

GC Olfactometry: (E/Z)=45:55, both isomers smell musky, the E-isomer ismore intense.

Example 4 a: (2″E/Z) Butyric acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester

Following the procedure for the synthesis of (2″-E/Z) acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 1), Steglich esterification of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (1.72 g, 8.59mmol) with butyric acid (2.43 ml, 26.4 mmol) and purification bysilica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.42) furnished 2.30 g (99%) ofthe odouriferous title compound.

IR (ATR): ν=1168/1073 cm⁻¹ (s, νC—O), 1739 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.90/0.92/0.93/0.94 (4d, J=6.5 Hz, 6H, 4″-Me₂), 0.95/0.96(2t, J=7.5 Hz, 3H, 4-H₃), 1.14/1.15 (2d, J=6.5 Hz, 3H, 1″-Me), 1.17/1.18(2s, 6H, 2′-Me₂), 1.60/1.68 (2d, J=1.5 Hz, 3H, 2″-Me), 1.62-1.70 (m, 2H,3-H₂), 2.32 (br. t, J=7.5 Hz, 2H, 2-H₂), 2.49/2.60 (2m_(c), 1H, 4″-H),3.90/3.91/3.99/4.00 (4d, J=11.0, 2H, 1′-H₂), 4.02/4.58 (2q, J=6.5 Hz,1H, 1″-H), 4.85/5.14 (2d, J=9.5 Hz, 1H, 3″-H).—¹³C NMR (CDCl₃):δ=11.2/17.8 (2q, 2″-Me), 13.7/13.7 (2q, C-4), 18.3/18.4 (2t, C-3),22.4/22.5/22.7/22.8/22.9/23.3 (6q, 1″-Me, 4″-Me₂), 23.4/23.5/23.7/23.7(4q, 2′-Me₂), 26.5/26.6 (2d, C-4″), 36.1/36.2 (2t, C-2), 66.1/73.5 (2d,C-1″), 69.6/69.8 (2t, C-1′), 74.3/74.4 (2s, C-2′), 131.7/132.0 (2d,C-3″), 136.5/136.8 (2s, C-2″), 173.4/173.5 (2s, C-1).—MS (70 eV);m/z=270 (1) [M⁺], 255 (1) [M⁺-CH₃], 143 (30) [C₈H₁₅O₂ ⁺], 127 (8)[C₈H₁₅O⁺], 111 (79) [C₈H₁₅ ⁺], 95 (25) [C₈H₁₄ ⁺—CH₃], 81 (10) [C₈H₁₄⁺—C₂H₅], 71 (100) [C₄H₇O⁺], 69 (48) [C₈H₁₄ ⁺—C₃H₅], 43 (48) [C₃H₇ ⁺].

Odour description: musky, fruity, animalic.

b: Butyric acid 2′-methyl-2′-(1″,2″,4″-trimethylpentyloxy)propyl ester

A suspension of butyric acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (1.00 g,3.70 mmol) and 10% Pd/C (100 mg, 0.09 mmol) in EtOAc (12 ml), was triceevacuated and flushed with N₂. Following two cycles of flushing andevacuating with H₂, the reaction mixture was stirred at room temp. for 3h under a positive pressure of H₂. The catalyst was removed by vacuumfiltration over a pad of Celite, and the filtrate was concentrated underreduced pressure. Silica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.40) of theresulting residue furnished 980 mg (98%) of the odouriferous titlecompound.

IR (ATR): ν=1168/1105/1072 cm⁻¹ (s, νC—O), 1739 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.82/0.84 (2d, J=7.0 Hz, 3H, 2″-Me), 0.85/0.90 (2d, J=7.0 Hz,6H, 4″-Me₂), 0.93-1.16 (m, 2H, 3″-H₂), 0.95/0.96 (2t, J=7.5 Hz, 3H,4-H₃), 0.99/1.03 (2d, J=6.5 Hz, 3H, 1″-Me), 1.18 (br. s, 6H, 2′-Me₂),1.62 (m_(c), 2H, 2″-,4″-H), 1.68 (m_(c), 2H, 3-H₂), 2.32/2.33 (2t, J=7.5Hz, 2H, 2-H₂), 3.54 (m_(c), 1H, 1″-H), 3.94 (br. s, 2H, 1′-H₂).—¹³C NMR(CDCl₃): δ=13.7/13.9 (2q, C-4), 15.9/17.4 (2q, 2″-Me), 17.4/18.7 (2q,1″-Me), 18.4/18.4 (2t, C-3), 21.6/22.0/23.7/23.7 (4q, 4″-Me₂),23.8/23.8/23.9/24.0 (4q, 2′-Me₂), 25.2/25.3 (2d, C-4″), 36.2/36.3 (2t,C-2), 36.8/37.1 (2d, C-2″), 40.9/43.0 (2t, C-3″), 70.1/70.3 (2t, C-1′),70.8/71.4 (2d, C-1″), 73.6/73.7 (2s, C-2′), 173.4/173.5 (2s, C-1).—MS(70 eV); m/z=187 (1) [M⁺-C₆H₁₃], 171 (2) [M⁺-C₅H₉O], 143 (75) [C₈H₁₅O₂⁺], 113 (27) [C₈H₁₇ ⁺], 71 (100) [C₄H₇O⁺], 57 (30) [C₄H₉ ⁺], 43 (44)[C₃H₇ ⁺].—C₁₆H₃₂O₃ (272.43): calcd. C, 70.54; H, 11.84. found C, 70.41;H, 11.73.

Odour description: musky, sweet, fruity, floral.

Example 5 (2″E/Z) Isobutyric acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester

Following the procedure for the synthesis of (2″E/Z) acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 1), Steglich esterification of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (1.72 g, 8.59mmol) with isobutyric acid (2.45 ml, 26.4 mmol) and purification bysilica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.50) furnished 1.94 g (84%) ofthe odouriferous title compound.

IR (ATR): ν=1072/1153 cm⁻¹ (s, νC—O), 1737 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.91/0.92/0.93/0.95 (4d, J=6.5 Hz, 6H, 4″-Me₂), 1.14/1.15(2d, J=6.5 Hz, 3H, 1″-Me), 1.17/1.18 (2s, 6H, 2′-Me₂), 1.19/1.20 (2d,J=6.5 Hz, 6H, 2-Me₂), 1.60/1.68 (2d, J=1.5 Hz, 3H, 2″-Me), 2.45-2.67 (m,1H, 2-H), 2.48/2.58 (2m_(c), 1H, 4″-H), 3.89/3.90/3.99/4.00 (4d, J=11.0,2H, 1′-H₂), 4.00/4.59 (2q, J=6.5 Hz, 1H, 1″-H), 4.85/5.14 (2d, J=9.5 Hz,1H, 3″-H).—¹³C NMR (CDCl₃): δ=11.2/17.8 (2q, 2″-Me),18.90/18.91/18.94/18.95 (4q, 2-Me₂), 22.4/22.5/22.7/22.8/22.9/23.2 (6q,1″-Me, 4″-Me₂), 23.4/23.5/23.7/23.8 (4q, 2′-Me₂), 26.5/26.6 (2d, C-4″),34.0/34.0 (2d, C-2), 66.1/73.5 (2d, C-1″), 69.6/69.7 (2t, C-1′),74.4/74.5 (2s, C-2′), 131.7/132.0 (2d, C-3″), 136.5/136.8 (2s, C-2″),176.7/176.8 (2s, C-1).—MS (70 eV); m/z=270 (1) [M⁺], 255 (1) [M⁺-CH₃],227 (1) [M⁺-C₃H₇], 143 (33) [C₈H₁₅O₂ ⁺], 127 (10) [C₈H₁₅O⁺], 111 (93)[C₈H₁₅ ⁺], 95 (29) [C₈H₁₄ ⁺—CH₃], 81 (13) [C₈H₁₄ ⁺—C₂H₅], 71 (100)[C₄H₇O⁺], 69 (57) [C₈H₁₄ ⁺—C₃H₅], 43 (80) [C₃H₇ ⁺].

Odour description: musky, fruity, rosy.

Example 6 (2″E/Z) 2-Methylacrylic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester

Following the procedure for the synthesis of (2″E/Z) acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 1), Steglich esterification of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (1.72 g, 8.59mmol) with 2-methylacrylic acid (2.45 ml, 26.4 mmol) and purification bysilica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.37) furnished 1.93 g (84%) ofthe odouriferous title compound.

IR (ATR): ν=1156/1073 cm⁻¹ (s, νC—O), 1721 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.91/0.92/0.93/0.95 (4d, J=6.5 Hz, 6H, 4″-Me₂), 1.14/1.15(2d, J=6.5 Hz, 3H, 1″-Me), 1.20/1.21 (2s, 6H, 2′-Me₂), 1.60/1.68 (2d,J=1.5 Hz, 3H, 2″-Me), 1.97 (m_(c), 3H, 2-Me), 2.45/2.61 (2m^(c), 1H,4″-H), 3.97/3.98/3.99/4.03 (4d, J=11.0, 2H, 1′-H₂), 4.07/4.60 (2q, J=6.5Hz, 1H, 1″-H), 4.85/5.14 (2d, J=9.5 Hz, 1H, 3″-H), 5.57/6.14 (m_(c), 2H,3-H₂).—¹³C NMR (CDCl₃): δ=11.2/17.7 (2q, 2″-Me),18.3/22.4/22.5/22.5/22.7/22.8/22.9/23.3 (8q, 2-Me, 1″-Me, 4″-Me₂),23.5/23.7/23.8/23.8 (4q, 2′-Me₂), 26.5/26.6 (2d, C-4″), 66.1/73.5 (2d,C-1″), 70.0/70.1 (2t, C-1′), 74.4/74.5 (2s, C-2′), 125.3/125.4 (2t,C-3), 131.7/132.0 (2d, C-3″), 136.3/136.4/136.5/136.8 (4s, C-2,-2″),167.1/167.2 (2s, C-1).—MS (70 eV); m/z=159 (1) [C₈H₁₅O₃ ⁺], 141 (22)[C₈H₁₃O₂ ⁺], 127 (6) [C₈H₁₅O⁺], 111 (44) [C₈H₁₅], 95 (18) [C₈H₁₄ ⁺—CH₃],85 (5) [C₄H₅O₂ ⁺], 81 (7) [C₈H₁₄ ⁺—C₂H₅], 69 (100) [C₄H₅O⁺], 55 (22)[C₄H₇ ⁺], 41 (35) [C₃H₅ ⁺].

Odour description: intense musky, slightly floral, fruity, rosy.

Example 7 (2E, 2″E/Z) But-2-enoic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester

Following the procedure for the synthesis of (2″E/Z) acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 1), Steglich esterification of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (1.72 g, 8.59mmol) with trans-crotonic acid (2.27 g, 26.4 mmol) and purification bysilica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.38) furnished 2.05 g (89%) ofthe odouriferous title compound.

IR (ATR): ν=1169/1074 cm⁻¹ (s, νC—O), 1722 cm⁻¹ (s, νO—C═O), 1660 cm⁻¹(s, νC═C).—¹H NMR (CDCl₃): δ=0.90/0.92/0.93/0.95 (4d, J=6.5 Hz, 6H,4″-Me₂), 1.14/1.15 (2d, J=6.5 Hz, 3H, 1″-Me), 1.19/1.20 (2s, 6H,2′-Me₂), 1.59/1.67 (2d, J=1.5 Hz, 3H, 2″-Me), 1.89/1.88 (2d, J=7.0 Hz,3H, 4-H₃), 2.46/2.60 (2m_(c), 1H, 4″-H), 3.95/3.96/4.02/4.04 (4d, J=11.0Hz, 2H, 1′-H₂), 4.05/4.59 (2q, J=6.5 Hz, 1H, 1″-H), 4.84/5.14 (2d, J=9.5Hz, 1H, 3″-H), 5.88 (br. dq, J=15.5, 1.5 Hz, 1H, 2-H), 6.97/7.01 (2dq,J=15.5, 7.0 Hz, 1H, 3-H).—¹³C NMR (CDCl₃): δ=11.2/17.8 (2q, 2″-Me),17.9/17.9 (2q, C-4), 22.4/22.5/22.5/22.7/22.9/23.3 (6q, 1″-Me, 4″-Me₂),23.5/23.6/23.7/23.8 (4q, 2′-Me₂), 26.5/26.6 (2d, C-4″), 66.1/73.5 (2d,C-1″), 69.5/69.6 (2t, C-1′), 74.5/74.5 (2s, C-2′), 122.5/122.7 (2d,C-2), 131.7/132.0 (2d, C-3″), 136.5/136.8 (2s, C-2″), 144.5/144.6 (2d,C-3), 166.3/166.3 (2s, C-1).—MS (70 eV); m/z=253 (1) [M⁺-CH₃], 159 (1)[C₈H₁₅O₃ ⁺], 141 (16) [C₈H₁₃O₂ ⁺], 127 (6) [C₈H₁₅O⁺], 111 (35) [C₈H₁₅⁺], 95 (14) [C₈H₁₄ ⁺—CH₃], 81 (7) [C₈H₁₄ ⁺—C₂H₅], 69 (100) [C₄H₅O⁺], 55(18) [C₄H₇ ⁺], 41 (21) [C₃H₅ ⁺].

Odour description: intense musky, fruity-floral undertones, sweet.

Example 8 (2″E/Z) But-3-enoic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester

Following the procedure for the synthesis of (2″E/Z) acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 1), Steglich esterification of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (1.72 g, 8.59mmol) with but-3-enoic acid (2.27 g, 26.4 mmol) and purification bysilica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.33) furnished 2.21 g (96%) ofthe odouriferous title compound.

IR (ATR): ν=1164/1073 cm⁻¹ (s, νC—O), 1741 cm⁻(s, νO—C═O), 1644 cm⁻¹ (s,νC═C).—¹H NMR (CDCl₃): δ=0.91/0.92/0.93/0.95 (4d, J=6.5 Hz, 6H, 4″-Me₂),1.13/1.14 (2d, J=6.5 Hz, 3H, 1″-Me), 1.17/1.18 (2s, 6H, 2′-Me₂),1.60/1.68 (2d, J=1.5 Hz, 3H, 2″-Me), 2.47/2.59 (2m_(c), 1H, 4″-H), 3.12(br. dt, J=7.0, 1.5 Hz, 2H, 2-H₂), 3.92/3.93/4.01/4.02 (4d, J=11.0 Hz,2H, 1′-H₂), 3.97/4.57 (2q, J=6.5 Hz, 1H, 1″-H), 4.85/5.14 (2d, J=9.5 Hz,1H, 3″-H), 5.15-5.20 (m, 2H, 4-H₂), 5.96 (m_(c), 1H, 3-H).—¹³C NMR(CDCl₃): δ=11.2/17.8 (2q, 2″-Me), 22.4/22.5/22.5/22.7/22.8/23.3 (6q,1″-Me, 4″-Me₂), 23.5/23.6/23.7/23.7 (4q, 2′-Me₂), 26.5/26.6 (2d, C-4″),39.1/39.2 (2t, C-2), 66.2/73.5 (2d, C-1″), 70.1/70.2 (2t, C-1′),74.3/74.4 (2s, C-2′), 118.5/118.6 (2t, C-4), 125.3/125.4 (2t, C-4),130.2/132.0 (2d, C-3″), 131.7/131.7 (2d, C-3), 136.5/136.8 (2s, C-2″),171.3/171.3 (2s, C-1).—MS (70 eV); m/z=268 (1) [M⁺], 253 (1) [M⁺-CH₃],141 (28) [C₈H₁₃O₂ ⁺], 127 (5) [C₈H₁₅O⁺], 111 (56) [C₈H₁₅ ⁺], 95 (26)[C₈H₁₄ ⁺—CH₃], 85 (8) [C₄H₅O₂ ⁺], 81 (9) [C₈H₁₄ ⁺—C₂H₅], 69 (100)[C₄H₅O⁺], 55 (29) [C₄H₇ ⁺], 41 (51) [C₃H₅ ⁺].

Odour description: strong musky with fruit-green nuances, floral.

Example 9 (2″E/Z) Propionic acid (1″,2″,4″-trimethylpent-2″-enyloxy)carbonylmethyl ester

A solution of N,N′-dicyclohexylcarbodiimide (DCC, 5.99 g, 29.0 mmol) inCH₂Cl₂ (13 ml) was added dropwise to a stirred solution of3,5-dimethylhex-3-en-2-o (4.00 g, 9.36 mmol) and4-(dimethylamino)pyridine (DMAP, 320 mg, 2.64 mmol) in CH₂Cl₂ (26 ml).The reaction mixture was stirred for 5 min. at room temp., prior tovacuum filtration of the yellow precipitate. The precipitate was washedwith CH₂Cl₂ (2×), and the combined filtrates were concentrated underreduced pressure. The crude material (7.70 g) was purified by silica-gelFC (pentane/Et₂O, 19:1, R_(f)=0.54) to provide 1.15 g (60%) ofchloroacetic acid 1′,2′,4′-trimethylpent-2′-enyl ester.

A mixture of chloroacetic acid 1′,2′,4′-trimethylpent-2′-enyl ester(1.09 g, 5.33 mmol), propionic acid (0.39 g, 5.33 mmol) and K₂CO₃ (1.47g, 10.6 mmol) in Et₂CO/dioxane (4:1, 12.5 ml) was refluxed for 2 days,with another portion of K₂CO₃ (1.47 g, 10.6 mmol) being added after 1day. The reaction mixture was then poured into ice/water (1:1, 50 ml),and the product was extracted with Et₂O (2×50 ml). The combined etherealextracts were washed with water (50 ml) and brine (25 ml), dried(Na₂SO₄) and concentrated under reduced pressure. Silca-gel FC(pentane/Et₂O, 19:1, R_(f)=0.23) of the resulting residue afforded 0.71g (55%) of the odouriferous the compound.

IR (ATR): ν=1162/1059 cm⁻¹ (s, νC—O), 1748 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.91/0.93/0.94/0.96 (4d, J=6.5 Hz, 6H, 4″-Me₂), 1.19 (t,J=7.5 Hz, 3H, 3-H, 3-H₃), 1.31/1.32 (2d, J=6.5 Hz, 3H, 1″-Me), 1.62/1.66(2d, J=1.5 Hz, 3H, 2″-Me), 2.45/2.46 (2q, J=8.0 Hz, 2H, 2-H₂), 2.65/2.68(2m_(c), 1H, 4″-H), 4.53/4.57 (2d, J=17.0 Hz, 1H, 2′-H_(b)), 4.59/4.61(2d, J=17.0 Hz, 1H, 2′-H_(a)), 5.07/5.27 (2 br. d, J=10.0 Hz, 1H, 3″-H),5.31/5.84 (2q, J=6.5 Hz, 1H, 1″-H).—¹³C NMR (CDCl₃): δ=8.89/8.89 (2q,C-3), 17.5/18.0 (2q, 2″-Me), 23.0/23.3/26.6/26.7/27.0/27.1 (6q,1″-,4″-Me₂), 26.6/26.7 (2d, C-4″), 27.0/27.2 (2t, C-2), 60.6/60.7 (t,C-2′), 70.4/76.9 (2d, C-1″), 130.6/131.2 (2s, C-2″), 135.5/136.6 (2d,C-3″), 167.0/167.1 (s, C-1′), 173.6/173.6 (s, C-1).—MS (70 eV); m/z=242(1) [M⁺], 128 (4) [C₈H₁₆O⁺], 115 (80) [C₅H₇O+], 110 (54) [C₈H₁₄ ⁺], 95(86) [C₈H₁₄ ⁺—CH₃], 87 (39) [C₄H₇O₂ ⁺], 81 (16) [C₈H₁₄ ⁺—C₂H₅], 67 (39)[C₈H₁₄ ⁺—C₃H₇], 57 (100) [C₄H₉ ⁺].

Odour description: musky, sweet, green, fruity.

Example 10(2′E/Z)-6-Methyl-6-(1′,2′,4′-trimethylpent-2′-enyloxy)heptan-3-one

A solution of pyridinium chlorochromate (PCC, 43.3 g, 201 mmol) inCH₂Cl₂ (350 ml) was added in one dash to a stirred slurry of Celite® (50g) in CH₂Cl₂ (900 ml). Stirring was continued for 15 min., prior todropwise addition of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propan-1-ol (see Example1, 11.8 g, 58.9 mmol) in CH₂Cl₂ (350 ml) in the course of 20 min. Thereaction mixture was stirred at room temp. for 1 d, with a furtherportion of PCC (4.30 g, 20.0 mmol) being added after the first 5 h, andthen filtered by suction over a pad of Celite®. The filtrate wasconcentrated in a rotary evaporator, and the resulting residue purifiedby silica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.57) to furnish 9.97 g(85%) of 2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propionaldehyde.

A solution of diethyl (2-oxobutyl)phosophonate (5.25 g, 25.2 mmol) inDME (5 ml) was added dropwise to a stirred suspension of 95% NaH (640mg, 25.2 mmol) in DME (15 ml). The reaction mixture was refluxed for 15min. prior to the dropwise addition of2-methyl-2-(1′,2′,4′-trimethylpent-2′-enyloxy)propionaldehyde (5.00 g,25.2 mmol). After further 2 h at reflux, the reaction mixture was pouredinto ice/water (1:1, 100 ml), acidified with AcOH, and extracted withEt₂O (2×50 ml). The combined ethereal extracts were washed with water(50 ml) and brine (25 ml), dried (Na₂SO₄) and concentrated under reducedpressure. Silica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.22) of theresulting residue provided 2.11 g (33%) of6-methyl-6-(1′,2′,4′-trimethylpent-2′-enyloxy)hept-4-en-3-one,possessing a relatively weak green, floral and cinnamic odor withoutpronounced musk character.

Under an atmosphere of N₂, [(PPh₃)CuH]₆ (5.83 g, 2.97 mmol) wasdissolved in deoxygenated benzene. After stirring for 5 min.,6-methyl-6-(1′,2′,4′-trimethylpent-2′-enyloxy)hept-4-en-3-one (2.05 g,8.12 mmol) was added dropwise during 5 min., and the reaction mixturewas stirred 5 h at room temp. under an atmosphere of N₂. Then the inertgas supply was removed, and the dark red suspension was stirred underhumid air for 30 min., during which the color of the reaction mixtureturned dark brown. The insoluble material was removed by vacuumfiltration over a pad of Celite® and washed with toluene, and thecombined organic solutions were evaporated in a rotary evaporator. Theresulting residue was purified by silica-gel FC (pentane/Et₂O, 19:1,R_(f)=0.14) to furnish 1.68 g (81%) of the odouriferous title compound.

IR (ATR): ν=1112 cm⁻¹ (s, νC—O), 1716 cm⁻¹ (s, νC═O).—¹H NMR (CDCl₃):δ=0.90/0.91/0.91/0.93 (4d, J=7.0 Hz, 6H, 4′-Me₂), 1.05/1.06 (2t, J=7.0Hz, 3H, 1-H₃), 1.11/1.12 (2d, J=6.5 Hz, 3H, 1′-Me), 1.11/1.14 (2s, 6H,6-Me₂), 1.16-1.77 (m, 2H, 5-H₂), 1.58/1.67 (2d, J=1.5 Hz, 3H, 2′-Me),2.41-2.63 (m, 5H, 2-,4-H₂, 4′-H), 3.92/4.49 (2q, J=6.5 Hz, 1H, 1′-H),4.83/5.10 (2 br. d, J=9.5 Hz, 1H, 3′-H).—¹³C NMR (CDCl₃): δ=7.85/7.87(2q, C-1), 11.3/17.9 (2q, 2′-Me), 22.5/22.6/22.8/22.9/23.5/26.0 (6q,1′-,4′-Me₂), 26.5/26.6 (2d, C-4′), 34.9/35.0/35.8/35.9/37.2/37.3 (6t,C-2,-4,-5), 65.4/74.7 (2d, C-1′), 72.9/74.6 (2s, C-6), 131.6/131.9 (2s,C-2′), 136.7/136.9 (2d, C-3′), 211.8 (s, C-3).—MS (70 eV); m/z=254 (1)[M⁺], 211 (1) [M⁺-C₃H₇], 145 (2) [C₈H₁₇O₂ ⁺], 127 (89) [C₈H₁₅O⁺], 111(42) [C₈H₁₅ ⁺], 110 (32) [C₈H₁₄ ⁺], 95 (36) [C₈H₁₄ ⁺—CH₃], 85 (7)[C₈H₁₅O⁺—C₃H₆], 69 (44) [C₈H₁₄ ⁺—C₃H₅], 57 (100) [C₄H₉ ⁺].

Odour description: powerful, pleasant musky note, sweet, fruity.

Example 11 6-Methyl-6-(1′,2′,4′-trimethylpentyloxy)heptan-3-one

Following the procedure for the preparation of butyric acid2′-methyl-2′-(1″,2″,4″-trimethylpentyloxy)propyl ester (see Example 4)(2′E/Z)-6-methyl-6-(1′,2′,4′-trimethylpent-2′-enyloxy)heptan-3-one (1.07g, 4.21 mmol) was hydrogenated in the presence of 10% Pd/C (100 mg, 0.09mmol) to provide after purification by bulb-to-bulb distillation (125°C., 0.9 mbar) 750 mg (70%) of the odouriferous title compound.

IR (ATR): ν=1108 cm⁻¹ (s, νC—O), 1716 cm⁻¹ (s, νC═O).—¹H NMR (CDCl₃):δ=0.80/0.83 (2 br. d, J=7.0 Hz, 6H, 4′-Me₂), 0.89/0.90/0.95/0.99 (4d,J=6.5 Hz, 6H, 1′-,2′-Me), 1.06/1.06 (2t, J=7.5 Hz, 3H, 1-H₃),1.10/1.11/1.14/1.14 (4s, 6H, 6-Me₂), 1.22-1.79 (m, 6H, 5-,3′-H₂,2′-,4′-H), 2.42-2.54 (m, 4H, 2-,4-H₂), 3.44/3.47 (2q, J=6.5, 4.5 Hz, 1H,1′-H).—¹³C NMR (CDCl₃): δ=7.88/7.88 (2q, C-1), 13.9/16.0/17.1/18.4 (4q,1′-,2′-Me), 21.7/22.1/23.6/24.1/25.6125.7/26.2/26.4 (8q, 6-,4′-Me₂),25.2/25.3 (2d, C-4′), 35.8/35.8/35.9/36.1/37.2/37.3 (6t, C-2,-4,-5),36.8/37.1 (2d, C-2′), 40.7/43.2 (2t, C-3′), 70.0/70.6 (2d, C-1′),73.8/73.9 (2s, C-6), 211.8/211.9 (2s, C-3).—MS (70 eV); m/z=241 (1)[M⁺-CH₃], 171 (2) [C₁₁H₂₃O⁺], 127 (100) [C₈H₁₅O⁺], 113 (7) [C₈H₁₇ ⁺],109 (14) [C₈H₁₅O⁺—H₂O], 97 (6) [C₇H₁₃ ⁺], 71 (11) [C₅H₁₁ ⁺], 57 (85)[C₄H₉ ⁺].

Odor description: musky, sweet, slightly fruity-floral.

Example 12 (2″E)-Propionic acid2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)-propyl ester

Following the procedure of C. Börner, M. R. Dennis, E. Sinn, S.Woodward, Eur. J. Org. Chem. 2001, 2435-2446,(3E)-5,5-dimethylhex-3-en-2-one was prepared. Standard LAH reduction(vide supra) furnished (3E)-5,5-dimethylhex-3-en-2-ol after purificationby silica-gel FC (pentane/Et₂O, 4:1, R_(f)=0.31). Following the generalprocedure of Example 1 (3E)-5,5-dimethylhex-3-en-2-ol (29.4 g, 229 mmol)was etherified with isobutylene oxide (19.8 g, 275 mmol) to provideafter silica-gel FC (pentane/Et₂O, 9:1, R_(f)=0.27) 4.21 g (8%) of2-methyl-2-(1′,4′,4′-trimethylpent-2′-enyloxy)propan-1-ol. According tothe synthesis of (2″E/Z)-acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (videsupra), Steglich esterification of2-methyl-2-(1′,4′,4′-trimethylpent-2′-enyloxy)propan-1-01 (1.30 g, 6.49mmol) with propionic acid (480 mg, 6.49 mmol) and silica-gel FC(pentane/Et₂O, 19:1, R_(f)=0.14) furnished 1.37 g (82%) of theodouriferous title compound.

IR (ATR): ν=1169/1063 cm⁻¹ (s, νC—O), 1741 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.99 (s, 9H, 4″-Me₃), 1.16 (t, J=7.0 Hz, 3H, 3-H₃), 1.17 (d,J=6.5 Hz, 3H, 1″-Me), 1.19 (s, 6H, 2′-Me₂), 2.37 (q, J=7.0 Hz, 2H,2-H₂), 3.94 (d, J=11.0 Hz, 1H, 1′-H_(b)), 4.00 (d, J=11.0 Hz, 1H,1′-H_(a)), 4.14 (quint. d, J=6.5, 1.0 Hz, 1H, 1″-H), 5.34 (dd, J=15.5,6.5 Hz, 1H, 2″-H), 5.54 (dd, J=15.5, 1.0 Hz, 1H, 3″-H).—¹³C NMR (CDCl₃):δ=9.09 (q, C-3), 23.8/23.9/23.9 (3q, 2′-,1″-Me), 27.6 (t, C-2), 29.4(3q, 4″-Me₃), 32.5 (s, C-4″), 69.1 (d, C-1″), 69.8 (t, C-1′), 74.4 (s,C-2′), 129.3 (d, C-2″), 140.3 (d, C-3″), 174.2 (s, C-1).—MS (70 eV);m/z=241 (1) [M⁺-CH₃], 129 (20) [C₈H₁₇O⁺], 127 (9) [C₈H₁₅O⁺], 111 (100)[C₈H₁₅ ⁺], 95 (16) [C₇H₁₁ ⁺], 69 (43) [C₈H₁₄ ⁺—C₃H₅], 57 (92) [C₄H₉ ⁺].

Odour description: musky, sweet, green, grapefruit.

Example 13 (2″E)-Cyclopropanecarboxylic acid2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)propyl ester

According to the synthesis of (2″E/Z)acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 1), Steglich esterification of2-methyl-2-(1′,4′,4′-trimethylpent-2′-enyloxy)propan-1-ol (1.30 g, 6.49mmol) with cyclopropanecarboxylic acid (590 mg, 6.49 mmol) andsilica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.29) furnished 1.46 g (84%) ofthe odouriferous title compound.

IR (ATR): ν=1163/1063 cm⁻¹ (s, νC—O), 1731 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.86 (m_(c), 2H, 3-,4-H_(b)), 0.99 (s, 9H, 4″-Me₃), 1.02(m_(c), 2H, 3-,4-H_(a)), 1.17 (d, J=6.5 Hz, 3H, 1″-Me), 1.20 (s, 6H,2′-Me₂), 1.66 (m_(c), 1H, 2-H), 3.93 (d, J=11.5 Hz, 1H, 1′-H_(b)), 3.99(d, J=11.5 Hz, 1H, 1′-H_(a)), 4.13 (quint. d, J=6.5, 1.0 Hz, 1H, 1″-H),5.35 (dd, J=15.5, 6.5 Hz, 1H, 2″-H), 5.54 (dd, J=15.5, 1.0 Hz, 1H,3″-H).—¹³C NMR (CDCl₃): δ=8.33 (2t, C-3,-4), 12.9 (d, C-2),23.9/23.9/24.0 (3q, 2′-,1″-Me), 29.4 (3q, 4″-Me₃), 32.5 (s, C-4″), 69.1(d, C-1″), 69.8 (t, C-1′), 74.4 (s, C-2′), 129.3 (d, C-2″), 140.3 (d,C-3″), 174.6 (s, C-1).—MS (70 eV); m/z=253 (1) [M⁺-CH₃], 141 (13)[C₈H₁₃O₂ ⁺], 127 (9) [C₈H₁₅O⁺], 111 (78) [C₈H₁₅ ⁺], 95 (14) [C₇H₁₁ ⁺],69 (100) [C₈H₁₄ ⁺—C₃H₅], 41 (33) [C₃H₅ ⁺].

Odour description: musky, sweet, fruity, powdery, anisic.

Example 14 (2″E)-Butyric acid2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)-propyl ester

According to the synthesis of (2″E/Z)-acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 1), Steglich esterification of2-methyl-2-(1′,4′,4′-trimethylpent-2′-enyloxy)propan-1-ol (1.30 g, 6.49mmol) with butyric acid (570 mg, 6.49 mmol) and silica-gel FC(pentane/Et₂O, 19:1, R_(f)=0.26) furnished 1.45 g (83%) of theodouriferous title compound.

IR (ATR): ν=1168/1062 cm⁻¹ (s, νC—O), 1738 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.96 (t, J=7.5 Hz, 3H, 4-H₃), 0.99 (s, 9H, 4″-Me₃), 1.16 (d,J=6.5 Hz, 3H, 1″-Me), 1.20 (s, 6H, 2′-Me₂), 1.68 (sext., J=7.5 Hz, 2H,3-H₂), 2.33 (t, J=7.5 Hz, 2H, 2-H₂), 3.94 (d, J=11.5 Hz, 1H, 1′-H_(b)),4.02 (d, J=11.0 Hz, 1H, 1′-H_(a)), 4.13 (quint. d, J=6.5, 1.0 Hz, 1H,1″-H), 5.35 (dd, J=15.5, 6.5 Hz, 1H, 2″-H), 5.54 (dd, J=15.5, 1.0 Hz,1H, 3″-H).—¹³C NMR (CDCl₃): δ=13.7 (q, C-4), 18.4 (t, C-3),23.8/23.9/24.0 (3q, 2′-,1″-Me), 29.4 (3q, 4″-Me₃), 32.5 (s, C-4″), 36.2(t, C-2), 69.1 (d, C-1″), 69.7 (t, C-1′), 74.4 (s, C-2′), 129.3 (d,C-2″), 140.3 (d, C-3″), 173.4 (s, C-1).—MS (70 eV); m/z=143 (15)[C₈H₁₅O₂ ⁺], 127 (10) [C₈H₁₅O⁺], 111 (100) [C₈H₁₅ ⁺], 95 (16) [C₇H₁₁ ⁺],71 (66) [C₄H₇O⁺], 69 (39) [C₈H₁₄ ⁺—C₃H₅], 55 (29) [C₄H₇ ⁺], 43 (41)[C₃H₇ ⁺].

Odour description: fruity, musky.

Example 15 (2′E)-4-Oxopentanoic acid 1′,4′,4′-trimethylpent-2′-enylester

Steglich esterification of (3E)-5,5-dimethylhex-3-en-2-ol (760 mg, 5.93mmol), following the general synthesis protocol described above, with4-oxopentanoic acid (690 mg, 5.93 mmol) gave after the usual work-up andpurification by silica-gel FC (pentane/Et₂O, 9:1, R_(f)=0.14) 1.21 g(90%) of the odouriferous title compound.

IR (ATR): ν=1721 cm⁻¹ (s, νC═O), 1159 cm⁻¹ (s, νC—O),.—¹H NMR (CDCl₃):δ=1.00 (s, 9H, 4′-Me₃), 1.28 (d, J=6.0 Hz, 3H, 1′-Me), 2.19 (s, 3H,5-H₃), 2.56 (t, J=7.0, 2H, 2-H₂), 2.74 (td, J=7.0, 2.5, 2H, 3-H₂),5.28-5.38 (m, 2H, 1′-,2′-H), 5.69 (d, J=14.5 Hz, 1H, 3′-H).—¹³C NMR(CDCl₃): δ=20.4 (q, 1′-Me), 28.4 (t, C-2), 29.3 (3q, 4′-Me₃), 29.8 (q,C-5), 32.7 (s, C-4), 37.9 (t, C-3), 71.6 (d, C-1′), 124.2 (d, C-2′),143.9 (d, C-3′), 171.9 (s, C-1), 206.6 (s, C-4).—MS (70 eV); m/z=208 (1)[M⁺-H₂O], 170 (5) [M⁺-C₄H₈ ⁺], 152 (1) [M⁺-C₄H₈—H₂O], 127 (11)[C₈H₁₅O⁺], 110 (16) [C₈H₁₅ ⁺], 99 (100) [C₅H₇O₂ ⁺], 95 (55) [C₈H₁₅⁺—CH₃], 81 (9) [C₅H₇O₂ ⁺—H₂O], 67 (25) [C₅H₇ ⁺], 55 (30) [C₄H₇ ⁺], 43(37) [C₂H₃O⁺].

Odour description: fresh, musky, slightly metallic, pear, ambrette seedoil.

Example 16 (2″E)-Propionic acid2′-(1″,4″-dimethylpent-2″-enyloxy)-2′-methylpropyl ester

Following the preparation of (2″E)-propionic acid2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)propyl ester (seeExample 12), standard LAH reduction of commercially available(3E)₅-methylhex-3-en-2-one (150 g, 1.34 mol) afforded at 74-80° C./160mbar 109 g (88%) of (3E)-5-methylhex-3-en-2-ol, of which 108 g (946mmol) was etherified with isobutylene oxide (81.8 g, 1.14 mmol) toprovide after silica-gel FC (pentane/Et₂O, 9:1, R_(f)=0.17) 24.8 g (14%)of 2-methyl-2-(1′,4′-dimethylpent-2′-enyloxy)propan-1-ol. Steglichesterification of 2-methyl-2-(1′,4′-dimethylpent-2′-enyloxy)propan-1-ol(1.80 g, 9.66 mmol) with propionic acid (1.19 g, 16.1 mmol) and usualwork-up with silica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.31) furnished1.00 g (43%) of the odouriferous title compound.

IR (ATR): ν=1168/1057 cm⁻¹ (s, νC—O), 1741 cm⁻¹ (s, νO—C═O).—¹H NMR(CDCl₃): δ=0.96/0.97 (2d, J=7.0 Hz, 6H, 4″-Me₂), 1.16 (t, J=7.5 Hz, 3H,3-H₃), 1.17 (d, J=6.5 Hz, 3H, 1″-Me), 1.20 (s, 6H, 2′-Me₂), 2.24 (br.oct., J=7.0 Hz, 1H, 4″-H), 2.37 (q, J=7.5 Hz, 2H, 2-H₂), 3.95 (d, J=11.5Hz, 1H, 1′-H_(b)), 3.99 (d, J=11.5 Hz, 1H, 1′-H_(a)), 4.12 (br. quint.,J=6.5 Hz, 1H, 1″-H), 5.38 (ddd, J=15.5, 6.5, 1.0 Hz, 1H, 2″-H), 5.50(ddd, J=15.5, 6.5, 1.0 Hz, 1H, 3″-H).—¹³C NMR (CDCl₃): δ=9.09 (q, C-3),21.2/22.2 (2q, 4″-Me), 23.7/23.8/23.9 (3q, 2′-,1″-Me), 27.6 (t, C-2),30.5 (d, C-4″), 68.8 (d, C-1″), 69.7 (t, C-1′), 74.4 (s, C-2′), 131.5(d, C-2″), 136.4 (d, C-3″), 174.2 (s, C-1).—MS (70 eV); m/z=227 (1)[M⁺-CH₃], 146 (1) [C₇H₁₄O₃ ⁺], 129 (15) [C₈H₁₇O⁺], 113 (8) [C₇H₁₃O⁺], 97(100) [C₇H₁₃ ⁺], 57 (80) [C₄H₉ ⁺], 55 (56) [C₇H₁₃ ⁺—C₃H₆].

Odour description: musky, fruity, earthy, green.

Example 17 (2″E)-Cyclopropanecarboxylic acid2′-(1″,4″-dimethylpent-2″-enyloxy)-2′-methylpropyl ester

Steglich esterification of2-methyl-2-(1′,4′-dimethylpent-2′-enyloxy)propan-1-ol (1.80 g, 9.66mmol) with cyclopropanecarboxylic acid (1.40 g, 16.1 mmol) and usualwork-up with silica-gel FC (pentane/Et₂O, 19:1, R_(f)=0.28) provided 900mg (37%) of the odouriferous title compound.

IR (ATR): ν=1162 cm⁻¹ (s, νC—O), 1730 cm⁻¹ (s, νO—C═O).—¹H NMR (CDCl₃):δ=0.86 (m_(c), 2H, 3-,4-H_(b)), 0.96/0.97 (2d, J=7.0 Hz, 6H, 4″-Me₂),1.02 (m_(c), 2H, 3-,4-H_(a)), 1.17 (d, J=6.5 Hz, 3H, 1″-Me), 1.21 (s,6H, 2′-Me₂), 1.65 (m_(c), 1H, 2-H), 2.24 (br. oct., J=7.0 Hz, 1H, 4″-H),3.94 (d, J=11.0 Hz, 1H, 1′-H_(b)), 3.98 (d, J=11.0 Hz, 1H, 1′-H_(a)),4.12 (br. quint., J=6.5 Hz, 1H, 1″-H), 5.39 (ddd, J=15.5, 6.5, 1.0 Hz,1H, 2″-H), 5.51 (ddd, J=15.5, 6.5, 1.0 Hz, 1H, 3″-H).—¹³C NMR (CDCl₃):δ=8.29/8.30 (2t, C-3,-4), 12.9 (d, C-2), 22.1/22.2 (2q, 4″-Me₂),23.7/23.8/23.9 (3q, 2′-,1″-Me), 30.5 (d, C-4″), 68.8 (d, C-1″), 69.7 (t,C-1′), 74.4 (s, C-2′), 131.5 (d, C-2″), 136.4 (d, C-3″), 174.6 (s,C-1).—MS (70 eV); m/z=239 (1) [M⁺-CH₃], 158 (1) [C₈H₁₄O₃ ⁺], 141 (13)[C₈H₁₃O₂ ⁺], 127 (1) [C₈H₁₅O⁺], 110 (12) [C₈H₁₄ ⁺], 97 (100) [C₇H₁₃ ⁺],69 (100) [C₄H₅O⁺], 55 (57) [C₇H₁₃ ⁺—C₃H₆], 41 (36) [C₃H₅ ⁺].

Odor description: musky, fruity, floral.

Example 18 Masculine Fine Fragrance

parts by weight compound/ingredient 1/1000 1.2-Acetyl-1,2,3,4,5,6,7,8-octahydro-1,2,8,8- 40.00 tetramethylnaphthalene(Georgywood ™) 2. Benzyl salicylate 150.00 3. Bergamot oil, Italy 10.004. Butyl hydroxy toluene 2.00 5. Cardamom oil, Guatemala 1.00 6.Cyclohexadec-5-ene-1-one (Velvione ™) 10.00 7.alpha-Cyclohexylidenebenzeneacetonitrile 60.00 (Peonile ™) 8.Diethylphthalate 285.00 9. Dihydro myrcenol 25.00 10.4-(1-Ethoxyethenyl)-3,3,5,5-tetramethylcyclohexanone 50.00 (Kephalis ™)11. Ethyl 2-ethyl-6,6-dimethyl-2-cyclohexencarboxylate 2.00(Givescone ™) 12. 6-Ethyl-3-methyloct-6-en-1-ol (Super Muguet ™) 13.0013. Grapefruit oil 5.00 14. Lavender oil, France 5.00 15. Linalool,synthetic 30.00 16. [1-Methyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl[methanol (Javanol ™) 1.00 17. Pepper oil 10.0018. Rose absolute 1.00 19. (2″EIZ) Cyclopropanecarboxylic acid2′-methyl- 300.00 2′-(1″,2″,4″-trimethylpent-2″-enytoxy) propyl ester1000.00

The (2″E/Z)-cyclopropanecarboxylic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester conveys tothis fragrance a very pleasant, sensual musk tonality. It adds volume,sweetness and warmth to the composition. In addition it providesfixative properties to the fragrance; yet, the musk characteristics arepresent from the top note impressions till the dry down of this perfume.

1. A compound of formula I

wherein R¹ and R³ are independently hydrogen, methyl, or ethyl; R² ishydrogen, methyl, ethyl, methylene, or ethylidene; R⁴ is C₁ to C₄ alkyl;or R⁴ is vinyl or a linear, branched or cyclic C₃ to C₄ alkenyl; X iscarbonyl or a divalent radical —(CMe₂)-; Y is oxygen or a divalentradical —(CH₂)—; the bond between C-2 and R² is a single bond, and thebond between C-2 and C-3 together with the dotted line represents adouble bond; or the bond between C-2 and C-3 is a single bond, and thebond between C-2 and R² together with the dotted line represents adouble bond; or the bond between C-2 and R² is a single bond and thebond between C-2 and C-3 is a single bond.
 2. A compound according toclaim 1 wherein the bond between C-2 and R² is a single bond, and thebond between C-2 and C-3 together with the dotted line represents adouble bond.
 3. A compound according to claim 1 selected from the groupconsisting of acetic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester, propionicacid 2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester,cyclopropanecarboxylic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester, butyricacid 2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester,isobutyric acid 2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propylester, 2-methylacrylic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester,but-2-enoic acid 2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propylester, but-3-enoic acid2′-methyl-2′-(1″,2″,4″-trimethylpent-2″-enyloxy)propyl ester, propionicacid (1″,2″,4″-trimethylpent-2″-enyloxy)carbonylmethyl ester,6-methyl-6-(1′,2′,4′-trimethylpent-2′-enyloxy)heptan-3-one, propionicacid 2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)propyl ester,cyclopropanecarboxylic acid2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)propyl ester, butyricacid 2′-methyl-2′-(1″,4″,4″-trimethylpent-2″-enyloxy)propyl ester,4-oxopentanoic acid 1′,4′,4′-trimethylpent-2′-enyl ester, propionic acid2′-(1″,4″-dimethylpent-2″-enyloxy)-2′-methylpropyl ester,cyclopropanecarboxylic acid2′-(1″,4″-dimethylpent-2″-enyloxy)-2′-methylpropyl ester, butyric acid2′-methyl-2′-(1″,2″,4″-trimethylpentyloxy)propyl ester, and6-methyl-6-(1′,2′,4′-trimethylpentyloxy)heptan-3-one.
 4. A compoundaccording to claim 2 characterised in that it is enriched in the(2″E)-isomer.
 5. A compound according to claim 2 characterised in thatit is enriched in the (2″Z)-isomer.
 6. A fragrance compositioncomprising a compound according to claim
 1. 7. (canceled)
 8. A fragranceapplication comprising a compound as defined in claim 1 or a mixturethereof.
 9. A fragrance application according to claim 8 wherein thefragrance application is a perfume, household product, laundry product,body care product or cosmetic product.
 10. A method of manufacturing afragrance application, comprising the step of incorporating a compoundof formula I as defined in claim 1 to a perfume, household product,laundry product, body care product or cosmetic product.
 11. A fragranceapplication comprising a compound as defined in claim 3, or a mixturethereof.